The present invention relates to the production of aralkyl tertiary hydroperoxides and more particularly to the production of p-diisopropylbenzene dihydroperoxide.
In the production of aralkyl tertiary polyhydroperoxides such as, for example, p-diisopropylbenzene dihydroperoxide, there is also produced the corresponding monohydroperoxide. Indeed, the rate of formation of the monohydroperoxide is approximately proportional to the concentration of the aryl tertiary alkane in the reaction mixture and that of the dihydroperoxide to the concentration of the monohydroperoxide. The reaction, however, comes to a virtual standstill before all of the monohydroperoxide is converted to the dihydroperoxide and consequently for a given amount of the aryl tertiary alkane only a small proportion of the dihydroperoxide is obtained.
It is known that the oxidation reaction can be conducted so as to yield a considerably higher amount of the aralkyl tertiary dihydroperoxide if the dihydroperoxide is separated from the oxidation reaction mixture alternately or concurrently with the oxidation reaction while the oxidation is continued with the remaining reaction mixture. As a practical matter, in a continuous reaction, the dihydroperoxide is continuously removed from the reaction mixture and the remaining portion of the oxidation reaction product is recycled to the oxidation reaction to convert the large amounts of monohydroperoxide present in the recycle stream to dihydroperoxide.
Unfortunately, the oxidation reaction product from which the dihydroperoxide has been removed and which is recycled to the oxidation reaction, in addition to containing large amounts of the monohydroperoxide and unreacted aryl tertiary alkane, also contains undesirable by-products and impurities which are quite detrimental to the efficiency of the oxidation reaction. For example, it is known that in such reactions keto aryl tertiary alkanols, aralkyl tertiary dialkanols and other by-products are are also produced. These materials, particularly the keto aryl tertiary alkanols hinder the oxidation reaction. As a consequence of the above-described recycle of the dihydroperoxide free oxidation reaction product to the oxidation reactor, these impurities and by-products continue to build up to the point where, if the oxidation reaction is to be conducted efficiently and economically, it may become necessary to completely discharge the reactor contents and charge the reactor with fresh reactants. Such a solution is both expensive and time consuming.